A simple advice : once you have made a progress you intent to keep with a page, don't forget to do:
VIEW>OBJECT MANAGER and lock objects which seem OK, like hyperlinks.
I won't discuss that not being knowledgable but some of my links moved from "Page in this project" to "smart link" . Can't at all figure out why. Maybe I used an option somewhere. With a locking, no more worry to have to review constantly your pages !